Clinical Outcomes of Carotid Angioplasty and Stenting for Radiation-associated Carotid Artery Stenosis

Objective: To investigate the procedural complication rate, restenosis rate, and clinical outcomes after carotid angioplasty and stenting in patients with radiation-associated carotid stenosis. Methods: All patients with a history of head and / or neck radiation referred to Queen Elizabeth Hospital, Hong Kong, for carotid angioplasty and stenting for carotid artery stenosis between January 2008 and December 2013 were identified. Their clinical information, and procedural and imaging findings were reviewed. All procedures were performed by a dedicated team of neurointerventionists. The mean degree of stenosis was 75.1% (range, 50.0%-94.1%). Standardised, regular postoperative follow-up with clinical and Doppler ultrasound assessments was scheduled for all patients. Results: Forty-five carotid arteries in 40 patients with a history of head and neck irradiation were stented in this study. The mean age was 63.3 years; 36 (90.0%) patients had radiotherapy for nasopharyngeal carcinoma. The mean time interval between radiotherapy and carotid angioplasty and stenting was 228.8 months (range, 8-487 months). The mean degree of stenosis was 75.1%. Fourteen (31.1%) patients who underwent carotid angioplasty and stenting had contralateral carotid artery occlusion. Embolic protection devices were used in 37 (82.2%) procedures. There was one (2.2%) procedural complication, with dissection of the left common carotid artery during catheterization for left internal carotid artery stenting. The mean follow-up period was 29 months (range, 1-66 months). The ipsilateral stroke-free survival rates were 97.8% at 6 months, 95.1% at 1 year, and 84.0% at 5 years. The restenosis-free survival rates were 95.0% at 6 months, 92.5% at 1 year, and 74.0% at 5 years. No 30-day mortality was identified. Two subarachnoid haemorrhages and one transient ischaemic attack occurred in the 30-day postoperative period. On subsequent follow-up, four (10.3%) patients died at a mean interval of 19 months after the procedure. Conclusion: We demonstrated that carotid angioplasty and stenting is safe in patients with radiation-associated carotid artery stenosis. The long-term clinical outcomes of ischaemic neurological event and restenosis were satisfactory.